diff options
Diffstat (limited to 'ice40')
| -rw-r--r-- | ice40/place_legaliser.cc | 47 |
1 files changed, 43 insertions, 4 deletions
diff --git a/ice40/place_legaliser.cc b/ice40/place_legaliser.cc index 0372ad6c..52a116b2 100644 --- a/ice40/place_legaliser.cc +++ b/ice40/place_legaliser.cc @@ -66,11 +66,11 @@ std::vector<CellChain> find_chains(const Context *ctx, F1 cell_type_predicate, F return chains; } -static void get_chain_midpoint(const Context *ctx, const std::vector<CellInfo *> &chain, float &x, float &y) +static void get_chain_midpoint(const Context *ctx, const CellChain &chain, float &x, float &y) { float total_x = 0, total_y = 0; int N = 0; - for (auto cell : chain) { + for (auto cell : chain.cells) { if (cell->bel == BelId()) continue; int bel_x, bel_y; @@ -89,6 +89,7 @@ class PlacementLegaliser { public: PlacementLegaliser(Context *ctx) : ctx(ctx){}; + bool legalise() { bool legalised_carries = legalise_carries(); @@ -98,6 +99,27 @@ class PlacementLegaliser } private: + void init_logic_cells() + { + for (auto bel : ctx->getBels()) { + // Initialise the logic bels vector with unavailable invalid bels, dimensions [0..width][0..height[0..7] + logic_bels.resize(ctx->chip_info->width + 1, + std::vector<std::vector<std::pair<BelId, bool>>>( + ctx->chip_info->height + 1, + std::vector<std::pair<BelId, bool>>(8, std::make_pair(BelId(), true)))); + if (ctx->getBelType(bel) == TYPE_ICESTORM_LC) { + // Using the non-standard API here to get (x, y, z) rather than just (x, y) + auto bi = ctx->chip_info->bel_data[bel.index]; + int x = bi.x, y = bi.y, z = bi.z; + IdString cell = ctx->getBoundBelCell(bel); + if (cell != IdString() && ctx->cells.at(cell)->belStrength >= STRENGTH_FIXED) + logic_bels.at(x).at(y).at(z) = std::make_pair(bel, true); + else + logic_bels.at(x).at(y).at(z) = std::make_pair(bel, false); + } + } + } + bool legalise_carries() { std::vector<CellChain> carry_chains = find_chains( @@ -108,13 +130,28 @@ class PlacementLegaliser [](const Context *ctx, const CellInfo *cell) { return net_only_drives(ctx, cell->ports.at(ctx->id("COUT")).net, is_lc, ctx->id("CIN"), false); }); - for (auto chain : carry_chains) { + int width = ctx->chip_info->width, height = ctx->chip_info->height; + for (auto &base_chain : carry_chains) { + std::vector<CellChain> split_chains = split_carry_chain(base_chain); + for (auto &chain : split_chains) { + float mid_x, mid_y; + get_chain_midpoint(ctx, chain, mid_x, mid_y); + float base_x = mid_x, base_y = mid_y - (chain.cells.size() / 16.0f); + // Find Bel meeting requirements closest to the target base + } } return true; } + // Find Bel closest to a location, meeting chain requirements + BelId find_closest_bel(float x, float y, int chain_size) + { + // TODO + return BelId(); + } + // Split a carry chain into multiple legal chains - std::vector<CellChain> split_carry_chain(Context *ctx, CellChain &carryc) + std::vector<CellChain> split_carry_chain(CellChain &carryc) { bool start_of_chain = true; std::vector<CellChain> chains; @@ -213,6 +250,8 @@ class PlacementLegaliser Context *ctx; std::unordered_set<IdString> rippedCells; std::unordered_set<IdString> createdCells; + // Go from X and Y position to logic cells, setting occupied to true if a Bel is unavailable + std::vector<std::vector<std::vector<std::pair<BelId, bool>>>> logic_bels; }; bool legalise_design(Context *ctx) |